ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1964 1/2 - 1965 => Topic started by: midlife on February 20, 2010, 09:51:52 PM

Title: Strange Underdash Harness Extension, 65GT
Post by: midlife on February 20, 2010, 09:51:52 PM

Today, I was refurbishing a customer's 1965 Pony Interior/GT version of the underdash harness.  It had a very strange extension from the gauge firewall plug on the main harness: a proper mate going to another firewall plug and wiring to a three-prong heater plug.  The extension had the markings of a C5BZ-18A366A, so it was obviously a Ford supplied extension.

I've never seen or heard of such a thing, but it appears that the main harness still had the standard wiring for the heater (early version), but this harness extension permitted the use of a later heater wiring system.  My guess is that the heater wiring changed sometime after the pony interior/GT option began in approx. Feb/March 2005 time frame.  I do have documentation that there were two heater wiring systems: one early, one late.  It appears this is a fairly early GT harness before they accommodated the revised heater system into the integral harness.

Does anyone know when the later heater version began?

Title: Re: Strange Underdash Harness Extension, 65GT
Post by: CharlesTurner on February 21, 2010, 12:20:48 AM

I've never seen one of those either.  It looks like someone adapted a later harness to work with the 3 wire heater motor and accompanying switch.  Very weird!

Title: Re: Strange Underdash Harness Extension, 65GT
Post by: Brant on February 21, 2010, 05:50:40 PM

I have a '65 GT350 with a scheduled production date of late March 1965.  It, of course, has the standard interior harness.  It has the three wire early heater blower motor, but it has this "jumper" as pictured above.  I always thought it was strange also.

I have not done any research to determine when the two wire motor started being used, but you have to think it was maybe sometime in April.  I think the parts book always lists it as April 1st like the switch.  Apparently, this harness had to be used for a period sometime in March (maybe Feb. and April too?). 

We even have this harness available as a reproduction.  I really don't know how long it was used, but it is quite interesting.

(http://www.virginiaclassicmustang.com/Assets/ProductImages/wg182.jpg)
http://www.virginiaclassicmustang.com/EARLY-65-HEATER-JUMPER-WIRING-HARNESS-AT-SWITCH-P5408.aspx (http://www.virginiaclassicmustang.com/EARLY-65-HEATER-JUMPER-WIRING-HARNESS-AT-SWITCH-P5408.aspx)

Title: Re: Strange Underdash Harness Extension, 65GT
Post by: J_Speegle on February 21, 2010, 06:59:27 PM

Thanks Brant - bet your not selling allot of those ;)  But glad they are available for the owners that need them

Title: Re: Strange Underdash Harness Extension, 65GT
Post by: midlife on February 21, 2010, 10:10:14 PM

That's the one!  It's very kewl that VA Classic has it; I'll keep you in mind in the future!

Thanks, Brant!